Magnetic recoil mechanism for guns



Oct. 18, 1955 J. H. RYAN ETAL 2,720,319

MAGNETIC RECOIL MECHANISM FOR GUNS Filed.May 25 1951 3 Sheets-Sheet 1 ByIltznaIcf P. Emil-.11. W dl fa w Oct. 18, 1955 J. H. RYAN ETAL 2,720,8 9

MAGNETIC RECOIL MECHANISM FOR GUNS s Sheets-Sheet 2 Filed May 25, 1951 1N VEN TORS James J- R EJ'L Dcn-lald'. P. Smi-Lh.

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HHCI neys Oct. 18, 1955 J. H. RYAN ETAL 2,720,819

MAGNETIC RECOIL. MECHANISM FOR GUNS Filed May 25, 1951 5 Sheets-Sheet 3 75 fires Assam INVENTORS. James H.E1 an yDunafd P. ErrfiU-L ail/QM United States Patent 2,720,819 MAGNETIC RECOIL MECHANISM FOR GUNS James H. Ryan, Morristown, Tenn., and Donald P. Smith, Maryland Park, Md., assignors to the United States of America as represented by the Secretary of the Army Application May 25, 1951, Serial No. 228,350 1 Claim. (Cl. 89-43) (Granted under Title 35, U. S. Code (1952), see. 266) The invention described in the specification and claim may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates generally to recoil mechanisms for guns and more particularly to a novel magnetic recoil mechanism adapted to effectively and efliciently bring a recoiling gun barrel to a smooth stop.

The problem of recoil in a weapon has long been a serious one and many attempts have been made to solve it with varying degrees of success. In small arms it is customary to require the body of the user to provide the necessary reaction and shock absorbing properties to stabilize the weapon after discharge and reposition it for the successive round. In the larger weapons it is mandatory for accurate firing that a firm mount or carriage be provided for the breech and barrel assembly. The conventional mount is firmly fixed and the breech, barrel and related appurtenances are free to move or slide relative thereto under the reaction of discharge. Under conditions of discharge large amounts of energy are released and imparted to the moving barrel assembly, which energy must be dissipated within a reasonable time and in a uniform manner to avoid damage or even destruction of the weapon.

The prior art discloses many means of accomplishing this energy dissipation including springs, dash-pots and the metered eseapement of fluids. Our invention, antithetically, uses the braking effect obtained when a mass of paramagnetic particles is subjected to a magnetic field to effectively and eificiently bring a recoiling gun barrel to a smooth stop and thereby eliminate the difficulties inherent in the prior art. It is accordingly a broad object of our invention to provide a shock absorbing device that will dissipate large amounts of kinetic energy without damage. It is a further object 'of our invention to provide a recoil mechanism for a gun that has few working parts and insures safety of operation with each cycle. Other objects and advantages of our invention will be apparent from the following specification in which:

Figure 1 is a plan view of a gun incorporating our recoil mechanism.

Figure 2 is a longitudinal section view of the gun of Figure 1 taken on lines 2- 2.

Figure 3 is a longitudinal section view of a modification of the invention of Figure 2.

Figure 4 is a cross section view taken on lines 44 of Figure 3.

Figure 5 is a cross section view taken on lines 55 of Figure3.

Figure 6 is an elevation of a gun showing a further modification of our invention.

Figure 7 is a schematic wiring diagram of the circuit of our invention.

Figure 8 is a schematic wiring diagram of a modification of the circuit of Figure 7.

Referring now to the figures wherein like reference characters indicate like parts, 1 indicates a barrel of conventional construction which may be rifled depending on the type of ordnance equipment and which terminates in a breech assembly which forms no part of our invention and is shown generally as 12.

Reference character 2 indicates with and firmly fixed to the barrel through the breech assembly 12; 3 indicates a steel or iron housing concentric with sleeve 2 and spaced therefrom whereby a volume is formed therebetween which volume is filled with a mass 4 of finely divided discrete paramagnetic particles such as iron particles for a purpose to be explained. Screwed or otherwise securely fixed to the sleeve 2 are a plurality of hooks 5 arranged in a plane transverse to the longitudinal axis of the sleeve and receiving therein one end of recuperator spring 6. End closers 7 and 8 are provided one at each end of the housing 3 and receive therein packing rings 9 for a purpose that will later appear. End closure 7 receives thereagainst the other end of spring 6. It should be noted that housing 3 is fixed by bolts to member 26 which connects with the gun cradle (not shown). Surrounding housing 3 and covering a substantial longitudinal length thereof is coil 10 which is adapted to be energized through lead 14 from a generator 16. The

a steel sleeve coaxial generator is preferably the direct current type and is supported from bracket 15 and driven cured to the shaft cooperating with pinion 18 which in turn meshes with gear 19 which is so arranged that its teeth mesh with rack 20 fastened to and movable with sleeve 2.

by spur gear 17 se- Operation A gun is a prime mover or heat engine in its broadest sense because power is produced and work is done from a force within the unit. The energy is released over such a short period of time that the motion of projectile and weapon is extremely violent. When a weapon using our invention is fired the barrel recoils carrying with it sleeve 2 and the recuperator spring starts to compress between pins 5 and end closure 7 thereby-absorbing and storing a part of the energy of recoil. Travel of the barrel and sleeve moves rack 20 with reference to gear 19 whereby the same is turnedand rapid rotation is imparted to the generator shaft. As the generator voltage builds up current flows from the armature thereof through the windings of coil 10 and a strong magnetic field is applied through the mass of paramagnetic particles 4. When a mass of contiguous discrete paramagnetic particles which are free to flow and are in actual contact one with the other and with the walls of the containing vessel is subjectedto a magnetic field the adhesive consistency or viscosity of the mass is increased and relative motion between the walls of the containing vessel is resisted with a force that is a function of field intensity. It can be seen that when the flux from coil 10 passes through the mass 4 the individual particles will become strongly attracted one to the other and to the housing wall 3 and sleeve 2. It is believed that the particles form chains extending in the direction of the lines of force. It can be readily seen that this strong adhesion force between the movable sleeve and the fixed housing applied by the mass of particles yields a braking force that can be varied at will by the proper selection of magnetic circuit constants such as the ampere turns, reluctance, etc. The maximum braking effect in this embodiment will be experienced at some time subsequent to firing'of the weapon which time is a function of the relation between build up time of the generator voltage and the build up time of the flux through the coil. As the sleeve slows under the braking effect of the energized mass of paramagnetic particles the generator output decays and the braking effect is cumulatively decreased. At complete rest in recoil position there is virtually no braking effect and the barrel is free to move forward to battery position under the urging of recuperator spring 6. In the return cycle the rotation of the generator may be utilized to again energize the coil to act as a counterrecoil brake or the generator may be equipped with a one-way clutch whereby the shaft does not rotate during this cycle and the conventional snub bers and shock absorbers may be provided and depended upon to stop the barrel in the battery position. It will of course be understood that the generator may be replaced by any source of electrical energy. Packing rings 9 held in end closures 7 and 8 keep the mass of particles confined to their intended volume during the movement of the sleeve.

A variant of our invention is revealed in Figures 3, 4 and wherein the recuperator spring means comprises a plurality of helical springs 28 arranged in juxtaposition around the periphery of sleeve 2 and, each spring being separately compartmented by a housing 30 which seals therein a light oil 32 and is fixed to housing 3. The springs 28 are confined between hooks 5 secured to sleeve 2 and one end of housing 30. When sleeve 2 moves under recoil carrying hooks 5 therewith each spring is uniformly compressed and the mass of paramagnetic particles is energized from any source of electromotive force through leads 14 to bring the sleeve to a smooth stop. The advantages of this species is that the mass of paramagnetic particles can in nowise interfere with the compression of the springs.

Figure 7 divulges a schematic wiring diagram of the circuit of our invention. Reference character 35 indicates a battery or any source of electrical energy which is connected through switch 36 which may be any known circuit making or breaking device to the coil 10 surrounding barrel 1.

In Figure 8 a wound resistor 38 which has an insulating portion 39 is mounted on the fixed coil or housing. Rider 40 is connected by rod 43 to the movable barrel or breech assembly. It will be readily seen that when the gun is fired the barrel, in moving will carry rod 43 with it and rider 40 will move from the insulated section 39 and establish contact through the resistance wires wound on solenoid 38. The circuit can be traced from battery 35 through leads 44, 45 and 46 to the solenoid windings, through rider 40, rod 43, flexible lead 42 and through the windings of the coil 10 back to the battery. It will be noted that since the barrel moves to the left the wiper 40 will establish contact with the solenoid 38 in such a position that the maximum resistance is in the circuit, thereby establishing the minimum braking at the time of maximum reaction force application to the barrel. As the barrel moves further back the resistance of the circuit is decreased and the coil current and flux build up until the barrel is in its position of full recoil at which time the braking is applied to produce a smooth stop.

A lubricant is a desirable addition to the paramagnetic particles in order to prevent undue wear on the surfaces exposed thereto and to permit smooth relative motion between the particles per se. Oil is a satisfactory lubricant but under the conditions of extreme heat likely to be encountered under rapid firing cycles a dry lubricant such as graphite, talc, French chalk or mica may be used.

In Figure 6 appears a further variant of our invention as applied to the breech of a conventional gun and including an anticipatory switch. It will be understood by those skilled in the art that it is frequently desirable to provide a way for the braking forces applied to the recoil to anticipate the discharge of the weapon. In the figure, reference character 1 indicates the barrel, 11 indicates the coil housing of Figure l surrounding the mass of paramagnetic particles (not shown), 12 indicates the breech ring assembly comprising a movable operating handle 48, a breech block 52 slidable in a plane transverse to the longitudinal axis of the barrel when handle 48 is rotated, a trigger shaft 53, an arm 54 slidable in housing 55 and having finger 51 bearing against trigger shaft 53. Switch is positioned close to and in the arcuate path of motion of trigger shaft 53. Lanyard 56 is fastened at one end to cleat 57 and passes over a system of pulleys for a purpose to be described. Leads 61 are connected .to any source of voltage and conduct electrical energy to coil 10 through leads 5% and 59. The operation of this species is as follows: when the lanyard 56 is pulled arm 54 is urged out of housing 55 and finger 51 starts to rotate trigger shaft 53. Before the trigger shaft has moved far enough in its arcuate path to fire the shell the switch 60 is closed by the trigger shaft 53 moving the handle thereof to the left. As soon as switch 60 is thrown the current flows in the windings of coil 10 and the flux starts to build up; shortly after the throwing of switch 60 the weapon fires and the barrel and breech assembly start to recoil. After the braking effect of the mass of paramagnetic particles has brought the barrel to a stop the recuperator springs will urge it forward and trigger shaft will engage the operating handle of switch 60 and throw it to the off position whereby the coil is de-energized for the next operation. It will be understood that the switch may be arranged to be opened when the barrel is in the full recoil position so that no braking effect is available to slow the barrel in its forward travel.

It will be apparent that the above-described embodiments are intended to be illustrative of some possible uses of our invention and We do not intend to be limited thereby as the scope of our invention will be indicated by the appended claim.

We claim:

A recoil mechanism for a gun comprising a support, a gun barrel movable in recoil and counterrecoil, a cham ber secured to said support coaxial with and surrounding said gun barrel, a mass of paramagnetic particles in said chamber and in normally loose frictional contact with said barrel, a magnetizing coil coaxial with and surrounding said chamber, a generator secured to said support, a gear train interconnecting said generator and said movable barrel to rotate said generator during barrel motion, said generator electrically connected to said coil to energize the same during said barrel motion whereby the said frictional contact is increased and barrel motion is resisted.

References Cited in the file of this patent UNITED STATES PATENTS 2,395,488 Lucht Feb. 26, 1946 2,442,371 Meyers et a1. June 1, 1948 2,454,818 Lucht Nov. 30, 1948 FOREIGN PATENTS 485,592 Belgium Nov. 13, 1948 December 18, 

